Kraft paper pulp is used to make a host of paper products including newsprint, catalog paper and grocery bags. The unprocessed kraft paper pulp which is used to make these products is often transported to a production facility in standard rectangular bales having a height in the range of 15" to 19", a width of between 24" to 36" and a length in the range of 24" to 36". The majority of unprocessed kraft paper bales are tightly wrapped with at least two transverse baling wires and anywhere from one to four longitudinal baling wires. These baling wires which may be round or oval in cross-sectional shape generally have a size in the range of 12 to 14 AWG.
It is essential for the safe and efficient operation of a paper production line that the baling wires which are used for wrapping kraft paper pulp bales be completely removed prior to introducing the unprocessed kraft paper into a production line. In the past, the removal of baling wires from bales of kraft paper has been accomplished manually, with the use of hand held wire cutters. However, the repetitive clenching hand motion that is associated with the continuous manual clipping and removal of baling wires from kraft paper bales has been known to cause carpel tunnel syndrome, a condition which is characterized by burning, aching, and numbness in the hand and wrist. Carpal tunnel syndrome is one of the most common occupational hazards in the pulp and paper industry. In addition, the manual removal of baling wires can often cause accidents when the baling wires suddenly snap free after being clipped. With these problems in mind, improvements have been made in the area of bale wire removal. In particular, automatic kraft paper bale wire removal systems have been introduced into paper production plants so as to improve the health and safety of factory workers in the pulp and paper industry and to ensure the efficient operation of paper production equipment.
A prior art automatic kraft bale dewiring system is manufactured by Lamb Canada Ltd. of Montreal, Quebec. The operational steps of Lamb's kraft bale dewiring system are illustrated schematically in FIGS. 1a-1d wherein the dewiring system is designated generally by reference numeral 10. The prior art kraft bale dewiring system 10 comprises a dewiring machine 12 having a remotely operated conveyor turntable 14 on which a bale of kraft paper 16 is loaded from a forklift truck into the dewiring system 10 with the longitudinal baling wires 18 running parallel to the flow of the bale 16 through the dewiring machine 12. Referring to FIG. 1b, the kraft paper bale 16 is clamped on its sides by opposed side clamps 20 and 22 and at its top by clamp 24 so as to firmly hold the bale 16 on the conveyor turntable 14 during the wire cutting operation. Referring to FIG. 1c, subsequently, a wire breaker blade 24, which travels beneath the kraft paper bale 16, engages and breaks each longitudinal baling wire 18 on the bale 16. Referring to FIG. 1d, thereafter, the bale clamps 20, 22 and 24 are retracted and a plurality of lift pegs 26 which are disposed beneath the bale 16 are actuated so as to raise the bale 16 off of the conveyor turntable 14. At such a time, a wire puller member 28, which travels across the top of the kraft paper bale 16, hooks each broken longitudinal baling wire 18 in succession so as to pull each broken baling wire 18 off of the bale 16 and out of the path of the conveyor 14.
Upon completing the wire cutting and removal operation, the kraft paper bale 16 is rotated on the conveyor 14 and the cutting and removal operation is repeated to fracture and remove the transverse baling wires from the kraft paper bale 16. Some prior art dewiring systems initially position the bale 16 so that the blade 26 and the wire puller 28 move diagonal to both the longitudinal and transverse wires so that only one diagonal movement of the breaker blade 26 and one diagonal movement of the puller 28 are required for each bale. Once the kraft paper bale 16 is completely dewired it is conveyed into the paper production line for conversion into paper products.
The prior art breaker blade 24 is illustrated in FIG. 2. Breaker blade 24 comprises a mounting portion 30 and a cutting portion 32. More particularly, mounting portion 30 includes a lower mounting flange 34 with opposed side mounting notches 36 and 38. The mounting portion is fashioned for removable installation in the dewiring machine 12. The cutting portion 32 of the prior art breaker blade 24 includes a leading edge 40 at the forward end thereof and a trailing edge 42 at the rearward end thereof. A ramped upper edge 44 having an angle of incline .alpha. extends from the leading edge 40 to a generally rectangular cutting notch 46. More particularly, the generally rectangular cutting notch 46 extends downwardly into the cutting portion 32 of the breaker blade 24. The breaker blade 24 further includes a single flat guide surface 48 disposed intermediate the rectangular cutting notch 46 and the rearward trailing edge 42 of the breaker blade 24 which is intended to maintain the breaker blade 24 in close proximity to the bottom of the bale 16 during cutting operation.
There are several deficiencies inherent in the design of the prior art breaker blade member 24. First, although the flat guide surface 48 is capable of maintaining position stability of the cutting portion 32 of breaker blade 24 during normal operating conditions, the blade 24 may encounter shocks or vibrations while traveling along its intended cutting path which could cause the prior art breaker blade 24 to shift or rock about its longitudinal axis. Consequently, the cutting portion 32 of the breaker blade 24 may not remain in close proximity to the bottom of the bale 16 and may fail to positively engage certain baling wires in the rectangular cutting notch 46.
Second, under certain abnormal operating conditions during which the breaker blade 24 encounters shocks or vibrations, baling wires 18 which may be engaged in the rectangular cutting notch 46 can slip out of the cutting notch 46 prior to being fractured.
Third, as a plurality of baling wires are engaged in succession, a leading baling wire may be urged out of the rectangular cutting notch 46 by trailing baling wires subsequently engaged in the cutting notch 46. As a consequence of the breaker blade failing to engage or retain certain baling wires, a kraft paper bale may exit the dewiring machine 12 and enter a paper production line with certain baling wires intact which could cause severe damage to expensive production machinery.
Therefore, it is an object of the subject invention to provide a new and improved breaker blade member for an automatic kraft bale dewiring machine having a cutting notch which is particularly adapted to securely engage and retain, until fracture, a plurality of baling wires.
It is another object of the subject invention to provide a new and improved breaker blade member for an automatic kraft bale dewiring machine having a plurality of flat guide surfaces to maintain position stability of the blade and maintain the blade in close proximity to the bottom of a kraft paper bale during normal and abnormal operating conditions.
The prior art wire puller member 28 is illustrated in FIG. 3. The wire puller member 28 basically comprises an engaging portion 50 and a mounting portion 52. More particularly, the mounting portion 52 includes a pair of spaced apart mounting apertures 54 and 56 extending therethrough for mounting the puller blade 28 to the dewiring machine 12. The engaging portion 50 of the prior art puller member 28 includes an arcuate forward leading edge 58, an intermediate ramped edge 60 and a rearward trailing edge 62. The prior art puller member 28 further includes a pair of spaced apart generally parallelogram shaped puller notches 64 and 66 which extend inwardly into the engaging portion 50 thereof.
There are several deficiencies inherent in the design of the prior art wire puller member 28. First, under certain operating conditions in which the puller member 28 encounters shocks or vibrations the puller notches 64 and 66 may fail to securely engage and retain one or more baling wires during a wire removal operation.
Second, as the puller member engages a plurality of baling wires in succession, a trailing baling wire may urge a leading baling wire out of one of the puller notches 64 and 66. Consequently, the kraft paper bale 16 may exit the dewiring machine 12 to be introduced into the paper production line with baling wires still wrapped around the bale 16 which could cause severe damage to production equipment.
Third, to fabricate the prior art puller member 28 several complex machining steps are necessarily required including intricate cutting procedures. In addition, the prior art puller member 28 comprises a substantial amount of plate material and thus is costly to manufacture.
Therefore, it is a another object of the subject invention to provide a new and improved wire puller member for an automatic kraft bale dewiring machine having a wire pulling notch which is particularly adapted to securely engage and retain one or more baling wires during a wire removal operation.
It is a further object of the subject invention to provide a new and improved wire puller member for an automatic kraft bale dewiring machine which is inexpensive to manufacture.